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-rw-r--r--lib/libpthread/thread/thr_priority_queue.c335
1 files changed, 335 insertions, 0 deletions
diff --git a/lib/libpthread/thread/thr_priority_queue.c b/lib/libpthread/thread/thr_priority_queue.c
new file mode 100644
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+++ b/lib/libpthread/thread/thr_priority_queue.c
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+/*
+ * Copyright (c) 1998 Daniel Eischen <eischen@vigrid.com>.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by Daniel Eischen.
+ * 4. Neither the name of the author nor the names of any co-contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY DANIEL EISCHEN AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+#include <stdlib.h>
+#include <sys/queue.h>
+#include <string.h>
+#ifdef _THREAD_SAFE
+#include <pthread.h>
+#include "pthread_private.h"
+
+/* Prototypes: */
+static void pq_insert_prio_list(pq_queue_t *pq, int prio);
+
+#if defined(_PTHREADS_INVARIANTS)
+
+static int _pq_active = 0;
+
+#define _PQ_IN_SCHEDQ (PTHREAD_FLAGS_IN_PRIOQ | PTHREAD_FLAGS_IN_WAITQ | PTHREAD_FLAGS_IN_WORKQ)
+
+#define _PQ_SET_ACTIVE() _pq_active = 1
+#define _PQ_CLEAR_ACTIVE() _pq_active = 0
+#define _PQ_ASSERT_ACTIVE(msg) do { \
+ if (_pq_active == 0) \
+ PANIC(msg); \
+} while (0)
+#define _PQ_ASSERT_INACTIVE(msg) do { \
+ if (_pq_active != 0) \
+ PANIC(msg); \
+} while (0)
+#define _PQ_ASSERT_IN_WAITQ(thrd, msg) do { \
+ if (((thrd)->flags & PTHREAD_FLAGS_IN_WAITQ) == 0) \
+ PANIC(msg); \
+} while (0)
+#define _PQ_ASSERT_IN_PRIOQ(thrd, msg) do { \
+ if (((thrd)->flags & PTHREAD_FLAGS_IN_PRIOQ) == 0) \
+ PANIC(msg); \
+} while (0)
+#define _PQ_ASSERT_NOT_QUEUED(thrd, msg) do { \
+ if ((thrd)->flags & _PQ_IN_SCHEDQ) \
+ PANIC(msg); \
+} while (0)
+
+#else
+
+#define _PQ_SET_ACTIVE()
+#define _PQ_CLEAR_ACTIVE()
+#define _PQ_ASSERT_ACTIVE(msg)
+#define _PQ_ASSERT_INACTIVE(msg)
+#define _PQ_ASSERT_IN_WAITQ(thrd, msg)
+#define _PQ_ASSERT_IN_PRIOQ(thrd, msg)
+#define _PQ_ASSERT_NOT_QUEUED(thrd, msg)
+#define _PQ_CHECK_PRIO()
+
+#endif
+
+
+int
+_pq_alloc(pq_queue_t *pq, int minprio, int maxprio)
+{
+ int ret = 0;
+ int prioslots = maxprio - minprio + 1;
+
+ if (pq == NULL)
+ ret = -1;
+
+ /* Create the priority queue with (maxprio - minprio + 1) slots: */
+ else if ((pq->pq_lists =
+ (pq_list_t *) malloc(sizeof(pq_list_t) * prioslots)) == NULL)
+ ret = -1;
+
+ else {
+ /* Remember the queue size: */
+ pq->pq_size = prioslots;
+
+ ret = _pq_init(pq);
+
+ }
+ return (ret);
+}
+
+int
+_pq_init(pq_queue_t *pq)
+{
+ int i, ret = 0;
+
+ if ((pq == NULL) || (pq->pq_lists == NULL))
+ ret = -1;
+
+ else {
+ /* Initialize the queue for each priority slot: */
+ for (i = 0; i < pq->pq_size; i++) {
+ TAILQ_INIT(&pq->pq_lists[i].pl_head);
+ pq->pq_lists[i].pl_prio = i;
+ pq->pq_lists[i].pl_queued = 0;
+ }
+
+ /* Initialize the priority queue: */
+ TAILQ_INIT(&pq->pq_queue);
+ _PQ_CLEAR_ACTIVE();
+ }
+ return (ret);
+}
+
+void
+_pq_remove(pq_queue_t *pq, pthread_t pthread)
+{
+ int prio = pthread->active_priority;
+
+ /*
+ * Make some assertions when debugging is enabled:
+ */
+ _PQ_ASSERT_INACTIVE("_pq_remove: pq_active");
+ _PQ_SET_ACTIVE();
+ _PQ_ASSERT_IN_PRIOQ(pthread, "_pq_remove: Not in priority queue");
+
+ /*
+ * Remove this thread from priority list. Note that if
+ * the priority list becomes empty, it is not removed
+ * from the priority queue because another thread may be
+ * added to the priority list (resulting in a needless
+ * removal/insertion). Priority lists are only removed
+ * from the priority queue when _pq_first is called.
+ */
+ TAILQ_REMOVE(&pq->pq_lists[prio].pl_head, pthread, pqe);
+
+ /* This thread is now longer in the priority queue. */
+ pthread->flags &= ~PTHREAD_FLAGS_IN_PRIOQ;
+
+ _PQ_CLEAR_ACTIVE();
+}
+
+
+void
+_pq_insert_head(pq_queue_t *pq, pthread_t pthread)
+{
+ int prio = pthread->active_priority;
+
+ /*
+ * Make some assertions when debugging is enabled:
+ */
+ _PQ_ASSERT_INACTIVE("_pq_insert_head: pq_active");
+ _PQ_SET_ACTIVE();
+ _PQ_ASSERT_NOT_QUEUED(pthread,
+ "_pq_insert_head: Already in priority queue");
+
+ TAILQ_INSERT_HEAD(&pq->pq_lists[prio].pl_head, pthread, pqe);
+ if (pq->pq_lists[prio].pl_queued == 0)
+ /* Insert the list into the priority queue: */
+ pq_insert_prio_list(pq, prio);
+
+ /* Mark this thread as being in the priority queue. */
+ pthread->flags |= PTHREAD_FLAGS_IN_PRIOQ;
+
+ _PQ_CLEAR_ACTIVE();
+}
+
+
+void
+_pq_insert_tail(pq_queue_t *pq, pthread_t pthread)
+{
+ int prio = pthread->active_priority;
+
+ /*
+ * Make some assertions when debugging is enabled:
+ */
+ _PQ_ASSERT_INACTIVE("_pq_insert_tail: pq_active");
+ _PQ_SET_ACTIVE();
+ _PQ_ASSERT_NOT_QUEUED(pthread,
+ "_pq_insert_tail: Already in priority queue");
+
+ TAILQ_INSERT_TAIL(&pq->pq_lists[prio].pl_head, pthread, pqe);
+ if (pq->pq_lists[prio].pl_queued == 0)
+ /* Insert the list into the priority queue: */
+ pq_insert_prio_list(pq, prio);
+
+ /* Mark this thread as being in the priority queue. */
+ pthread->flags |= PTHREAD_FLAGS_IN_PRIOQ;
+
+ _PQ_CLEAR_ACTIVE();
+}
+
+
+pthread_t
+_pq_first(pq_queue_t *pq)
+{
+ pq_list_t *pql;
+ pthread_t pthread = NULL;
+
+ /*
+ * Make some assertions when debugging is enabled:
+ */
+ _PQ_ASSERT_INACTIVE("_pq_first: pq_active");
+ _PQ_SET_ACTIVE();
+
+ while (((pql = TAILQ_FIRST(&pq->pq_queue)) != NULL) &&
+ (pthread == NULL)) {
+ if ((pthread = TAILQ_FIRST(&pql->pl_head)) == NULL) {
+ /*
+ * The priority list is empty; remove the list
+ * from the queue.
+ */
+ TAILQ_REMOVE(&pq->pq_queue, pql, pl_link);
+
+ /* Mark the list as not being in the queue: */
+ pql->pl_queued = 0;
+ }
+ }
+
+ _PQ_CLEAR_ACTIVE();
+ return (pthread);
+}
+
+
+static void
+pq_insert_prio_list(pq_queue_t *pq, int prio)
+{
+ pq_list_t *pql;
+
+ /*
+ * Make some assertions when debugging is enabled:
+ */
+ _PQ_ASSERT_ACTIVE("pq_insert_prio_list: pq_active");
+
+ /*
+ * The priority queue is in descending priority order. Start at
+ * the beginning of the queue and find the list before which the
+ * new list should be inserted.
+ */
+ pql = TAILQ_FIRST(&pq->pq_queue);
+ while ((pql != NULL) && (pql->pl_prio > prio))
+ pql = TAILQ_NEXT(pql, pl_link);
+
+ /* Insert the list: */
+ if (pql == NULL)
+ TAILQ_INSERT_TAIL(&pq->pq_queue, &pq->pq_lists[prio], pl_link);
+ else
+ TAILQ_INSERT_BEFORE(pql, &pq->pq_lists[prio], pl_link);
+
+ /* Mark this list as being in the queue: */
+ pq->pq_lists[prio].pl_queued = 1;
+}
+
+#if defined(_PTHREADS_INVARIANTS)
+void
+_waitq_insert(pthread_t pthread)
+{
+ pthread_t tid;
+
+ /*
+ * Make some assertions when debugging is enabled:
+ */
+ _PQ_ASSERT_INACTIVE("_waitq_insert: pq_active");
+ _PQ_SET_ACTIVE();
+ _PQ_ASSERT_NOT_QUEUED(pthread, "_waitq_insert: Already in queue");
+
+ if (pthread->wakeup_time.tv_sec == -1)
+ TAILQ_INSERT_TAIL(&_waitingq, pthread, pqe);
+ else {
+ tid = TAILQ_FIRST(&_waitingq);
+ while ((tid != NULL) && (tid->wakeup_time.tv_sec != -1) &&
+ ((tid->wakeup_time.tv_sec < pthread->wakeup_time.tv_sec) ||
+ ((tid->wakeup_time.tv_sec == pthread->wakeup_time.tv_sec) &&
+ (tid->wakeup_time.tv_nsec <= pthread->wakeup_time.tv_nsec))))
+ tid = TAILQ_NEXT(tid, pqe);
+ if (tid == NULL)
+ TAILQ_INSERT_TAIL(&_waitingq, pthread, pqe);
+ else
+ TAILQ_INSERT_BEFORE(tid, pthread, pqe);
+ }
+ pthread->flags |= PTHREAD_FLAGS_IN_WAITQ;
+
+ _PQ_CLEAR_ACTIVE();
+}
+
+void
+_waitq_remove(pthread_t pthread)
+{
+ /*
+ * Make some assertions when debugging is enabled:
+ */
+ _PQ_ASSERT_INACTIVE("_waitq_remove: pq_active");
+ _PQ_SET_ACTIVE();
+ _PQ_ASSERT_IN_WAITQ(pthread, "_waitq_remove: Not in queue");
+
+ TAILQ_REMOVE(&_waitingq, pthread, pqe);
+ pthread->flags &= ~PTHREAD_FLAGS_IN_WAITQ;
+
+ _PQ_CLEAR_ACTIVE();
+}
+
+void
+_waitq_setactive(void)
+{
+ _PQ_ASSERT_INACTIVE("_waitq_setactive: pq_active");
+ _PQ_SET_ACTIVE();
+}
+
+void
+_waitq_clearactive(void)
+{
+ _PQ_ASSERT_ACTIVE("_waitq_clearactive: ! pq_active");
+ _PQ_CLEAR_ACTIVE();
+}
+#endif
+#endif
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